The present invention relates to an airbag device which inflates an airbag to protect an occupant in a vehicle when the vehicle comes into collision.
An airbag device, which inflates an airbag thereof to protect an occupant in a vehicle in case of emergency such as the vehicle comes into collision, has a folded airbag, a member enclosing the airbag, and a gas generating device called as an inflator.
The inflator has a casing provided with openings as gas outlets, a gas generating agent filled in the casing, and an igniter to start reaction of the gas generating agent in such a manner that the igniter is actuated in case that a vehicle comes into collision.
An inflator disclosed in the U.S. Pat. No. 4,950,458 has a time-gas pressure characteristics where a gas generating pressure is relatively low at a beginning of operation thereof and is raised after a certain period of time has elapsed. The inflator of the U.S. Pat. No. 4,950,458 has an aluminum housing divided into two compartments. The inflator triggers a gas generating agent within one compartment at first, and then triggers a gas generating agent within the other compartment in a short lag so as to delay a rise of the gas pressure.
The inflator of the U.S. Pat. No. 4,950,458 is sure to trigger both the gas generating agent filled within both compartments, and all gases generated are fed into the airbag.